Laundry items, surgical tools or other medical materials must be cleaned and sterilized before they can be reused. Ordinarily this sterilization is performed by means of steam sterilization in sterilization chambers. In such a process saturated steam is fed into the sterilization chamber where it comes into direct contact with the objects to be sterilized. Maintaining specific process parameters, especially a precise temperature and constant pressure, is absolutely imperative to ensure proper sterilization. The process is monitored by means of appropriate devices.
U.S. Pat. No. 3,982,893 describes such a monitoring device. In it, sensors that continuously monitor the sterilization process can be arranged directly in the sterilization material. A digital signal is then generated from the measured values in an analog/digital converter, and is transmitted via radio to an antenna positioned inside the sterilization chamber. Via a cable that passes through the housing walls of the sterilization chamber, the antenna is connected to regulating or control devices. The apparatus thereby provides for a continuous monitoring and transmission of data. Although the arrangement of the sensors directly in the sterilization material and the transmission of the data via radio make it possible to detect the temperature inside the process material with greater precision, the passing of cables through the housing walls of the sterilization chamber is structurally costly. Furthermore, disruptions in radio contact render monitoring and verification of the sterilization process impossible.
EP 0 671 956 B1 provides for a testing unit to be positioned inside the chamber of a sterilization system. The components of this replaceable test module may comprise, for example, a temperature sensor and a pressure sensor. The testing unit is positioned at a location within the sterilizer that is near its outlet. There, the presence of air can be detected with particular accuracy using a temperature sensor. The data acquired by the testing unit are transmitted via radio to a receiver positioned outside the chamber, for real-time monitoring. When there are disruptions in radio contact, no measured data are available; thus the maintenance of process parameters can no longer be verified. As an alternative, the data may also be recorded internally, and then read out and evaluated only upon completion of the process. However in this case, problems cannot be detected in the process as it runs. A further disadvantage of this arrangement is that process data can be acquired at only a single location within the sterilizer. Furthermore, the testing unit comprises other devices for data processing and signal generation, so that the construction of a testing unit of this type is relatively costly.